FR2410404A1 - GAMMA CORRECTION CIRCUIT FOR TELEVISION - Google Patents
GAMMA CORRECTION CIRCUIT FOR TELEVISIONInfo
- Publication number
- FR2410404A1 FR2410404A1 FR7833436A FR7833436A FR2410404A1 FR 2410404 A1 FR2410404 A1 FR 2410404A1 FR 7833436 A FR7833436 A FR 7833436A FR 7833436 A FR7833436 A FR 7833436A FR 2410404 A1 FR2410404 A1 FR 2410404A1
- Authority
- FR
- France
- Prior art keywords
- gamma
- television
- signal
- correction circuit
- white level
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/20—Circuitry for controlling amplitude response
- H04N5/202—Gamma control
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Picture Signal Circuits (AREA)
- Processing Of Color Television Signals (AREA)
Abstract
CIRCUIT DE CORRECTION DE GAMMA POUR TELEVISION DANS LEQUEL UN CORRECTEUR DE GAMMA DELIVRE UN SIGNAL DE SORTIE AVEC UN GAMMA MINIMAL DE DEUX, TANDIS QUE, PAR RAPPORT A UN SIGNAL D'ENTREE LINEAIRE QUI EST LIMITE AU NIVEAU DU BLANC PAR UN CIRCUIT DE LIMITATION DE SIGNAL, ON DERIVE UN SIGNAL DE CORRECTION AYANT UNIQUEMENT DES VALEURS POSITIVES ET SERVANT A AUGMENTER LE GAMMA DU SIGNAL DE SORTIE DU CORRECTEUR DE GAMMA. ON EVITE AINSI QUE, LORS DE DEPASSEMENTS DU NIVEAU DU BLANC PROVOQUES PAR DES DETAILS DE SCENE, LA VISUALISATION DE LA SCENE SE FASSE AVEC UNE LUMINOSITE D'IMAGE PLUS BASSE QUE CELLE CORRESPONDANT AU NIVEAU DU BLANC. APPLICATION AUX TELEVISEURS EN NOIR ET BLANC.GAMMA CORRECTION CIRCUIT FOR TELEVISION IN WHICH A GAMMA CORRECTOR DELIVERS AN OUTPUT SIGNAL WITH A MINIMUM GAMMA OF TWO, WHILE, IN RELATION TO A LINEAR INPUT SIGNAL WHICH IS LIMITED TO THE WHITE LEVEL BY A LIMITING CIRCUIT OF SIGNAL, WE DERIVE A CORRECTION SIGNAL HAVING ONLY POSITIVE VALUES AND SERVING TO INCREASE THE GAMMA OF THE OUTPUT SIGNAL OF THE GAMMA CORRECTOR. IT IS THEREFORE AVOID THAT, WHEN THE WHITE LEVEL IS EXCEEDED BY SCENE DETAILS, THE VIEWING OF THE SCENE IS FALLING WITH A LOWER IMAGE BRIGHTNESS THAN THAT CORRESPONDING TO THE WHITE LEVEL. APPLICATION TO BLACK AND WHITE TELEVISIONS.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL7713052A NL7713052A (en) | 1977-11-28 | 1977-11-28 | GAMMA CORRECTION CIRCUIT FOR TELEVISION. |
Publications (1)
Publication Number | Publication Date |
---|---|
FR2410404A1 true FR2410404A1 (en) | 1979-06-22 |
Family
ID=19829631
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
FR7833436A Withdrawn FR2410404A1 (en) | 1977-11-28 | 1978-11-27 | GAMMA CORRECTION CIRCUIT FOR TELEVISION |
Country Status (9)
Country | Link |
---|---|
US (1) | US4227216A (en) |
JP (1) | JPS5483310A (en) |
CA (1) | CA1128652A (en) |
DE (1) | DE2850857A1 (en) |
FR (1) | FR2410404A1 (en) |
GB (1) | GB2009557B (en) |
IT (1) | IT1100199B (en) |
NL (1) | NL7713052A (en) |
SE (1) | SE7812106L (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3140230C2 (en) * | 1981-10-09 | 1989-08-31 | Siemens AG, 1000 Berlin und 8000 München | Circuit arrangement for the optional regulation of the gradation of television signals |
NL8200667A (en) * | 1982-02-19 | 1983-09-16 | Philips Nv | RANGE CORRECTION SWITCH FOR TELEVISION. |
JPS627290A (en) * | 1985-07-04 | 1987-01-14 | Fuji Photo Film Co Ltd | Gradient correction for color negative film picking up image and its device |
GB2211045B (en) * | 1987-10-10 | 1991-08-21 | Marconi Co Ltd | Linearity adjusting circuit |
GB2240001B (en) * | 1990-01-16 | 1993-12-22 | Rank Cintel Ltd | Film characteristic simulator |
GB2250886B (en) * | 1990-12-13 | 1995-06-14 | Rank Cintel Ltd | Noise reduction in video signals |
US6680755B2 (en) * | 2001-04-05 | 2004-01-20 | Industrial Technology Research Institute | Adjustable biased gamma-correction circuit with central-symmetry voltage |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3970774A (en) * | 1975-03-31 | 1976-07-20 | Rca Corporation | Electronic signal mixer |
GB1549769A (en) * | 1975-08-06 | 1979-08-08 | Rca Corp | Negative gamma circuit |
CA1101943A (en) * | 1975-10-22 | 1981-05-26 | Frederik J. Van Roessel | Video switching circuit |
-
1977
- 1977-11-28 NL NL7713052A patent/NL7713052A/en not_active Application Discontinuation
-
1978
- 1978-10-31 US US05/956,308 patent/US4227216A/en not_active Expired - Lifetime
- 1978-10-31 CA CA315,409A patent/CA1128652A/en not_active Expired
- 1978-11-24 DE DE19782850857 patent/DE2850857A1/en not_active Withdrawn
- 1978-11-24 SE SE7812106A patent/SE7812106L/en unknown
- 1978-11-24 IT IT30196/78A patent/IT1100199B/en active
- 1978-11-24 GB GB7845934A patent/GB2009557B/en not_active Expired
- 1978-11-25 JP JP14500078A patent/JPS5483310A/en active Pending
- 1978-11-27 FR FR7833436A patent/FR2410404A1/en not_active Withdrawn
Also Published As
Publication number | Publication date |
---|---|
GB2009557B (en) | 1982-07-07 |
SE7812106L (en) | 1979-05-29 |
IT7830196A0 (en) | 1978-11-24 |
US4227216A (en) | 1980-10-07 |
IT1100199B (en) | 1985-09-28 |
NL7713052A (en) | 1979-05-30 |
CA1128652A (en) | 1982-07-27 |
GB2009557A (en) | 1979-06-13 |
JPS5483310A (en) | 1979-07-03 |
DE2850857A1 (en) | 1979-05-31 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
ST | Notification of lapse |